The concept of activating, deactivating, or limiting the primary function of a device according to its environment using sensing technology is decades old. Examples include (1) garage door openers whose door-closing cycle is limited either by infrared (“IR”) beam detection of objects within the path of a closing garage door or by surges in the power consumed by the door-closing motor, and (2) light emitting devices such as outdoor floodlights with infrared detectors capable of sensing the presence of object(s) to activate/deactivate the floodlight. Over the years, various medical devices have incorporated similar sensing technologies to assist in gauging the proximity of a device to a target surface such as human tissue. However, medical devices using decades old sensing technology are subject to risk of producing unintended operation. For example, a typical heating lamp incorporating a proximity sensor comprising an infrared emitter and infrared-sensitive detector has an aperture or face of about two inches by four inches configured for emitting radiant heat energy from the lamp. With such lamps, the aperture must not be placed in direct contact with a patient, whereby the lamp utilizes its infrared sensor to bring the lamp to within an acceptable proximity of the target surface for desired operation. However, the infrared proximity sensor of such devices may not recognize a protruding non-flat surface, such as a person's nose, due to the requirement of reflection for proper sensor operation, thereby bringing the nose too close to the aperture and potentially causing a burn. In another instance, an infrared sensor may be brought too close to the skin, to within a range known as a “blind-spot,” a range directly in front of the sensor where the sensor cannot detect the skin surface due to the geometric requirements of infrared reflection sensing. As a result, the device may incorrectly identify a properly spaced surface and allow radiant heat exposure to occur, potentially burning a target patient.
Improvements in medical devices are always desired. Thus, what is desired is an energy emitting treatment device with a sensor means for detecting a target surface to be irradiated, the device incorporating one or more of the following characteristics: (1) a sensor means effective to sense a target surface about an entire aperture as opposed to one point or a plurality of points, (2) a sensor means allowing radiant energy to pass unhindered or unattenuated out from the device, (3) a sensor means that does not require an aperture to sense a target surface, (4) a sensor means that does not operate on the principles of reflection, e.g. infrared light reflecting off a target surface, (5) a sensor means that may be programmed to sense particular surfaces rather than any surface within the device's field, (6) a sensor means not requiring a minimum distance between a sensor of the device and a target surface in order for target surface detection to occur, and (7) a sensor means that is resistant to electromagnetic radiation about a spectrum from less than ultraviolet wavelengths to greater than infrared wavelengths.